The invention relates to a machine for manufacturing and packaging formed bodies of a moldable substance, comprising
a loading section, on which strip-shaped packaging material arranged at least approximately horizontally is longitudinally movable,
a shaping wheel which is rotatable about a central axis and has a cylindrical peripheral surface as well as a plurality of moulds disposed at angular intervals around said central axis,
a filling area, through which the moulds are movable in succession in order to be filled with substance,
a dwell area, after travelling through which the substance contained in the mould is a packageable formed body,
a deposit area which is disposed above the loading section in such a way that each formed body may be deposited from its mould directly on the packaging material, and
a device for wrapping the formed bodies situated on the packaging material.
A known machine of said type (brochure wa 704 of the company SIG Schweizerische Industrie-Gesellschaft, CH-8212 Neuhausen) is provided for manufacturing and packaging block-shaped formed bodies of butter. Said machine has a disk-shaped shaping wheel which is rotatable about a vertical axis and comprises a plurality of moulds of rectangular cross section which extend parallel to the axis of the shaping wheel from the top to the bottom surface of the latter. The shaping wheel is rotatable step by step; each time it stops, one of its moulds is situated in the filling area where it is filled with butter by a pumping set, while a previously filled mould now situated in the deposit area is emptied by the butter portion shaped in said mould being pressed downwards and taken over by a device which already holds a preformed and separated portion of the strip-shaped packaging material and completely encloses the butter portion in said packaging material portion.
From U.S. Pat. No. 1,524,915 a machine for manufacturing blocks or bricks from a plastic substance is known in which, disposed above a loading section, e.g. a conveyor, is a shaping wheel which is rotatable about a horizontal axis disposed at right angles to the loading section. The shaping wheel has radially disposed moulds which contain a piston each and in the radially retracted state of the piston are filled in a filling area and then travel through a compression area in which the substance is compressed by a compression shoe. Finally, the moulds travel through a deposit area in which under the control of a stationary central control cam their piston is displaced in a radially outward direction and ejects the block or brick produced in the mould so that the block or brick is deposited on the loading section. Feeding of packaging material along the loading section for packaging the blocks or bricks is not provided.
The same also applies to similar machines, known from WO 00/30458, for shaping three-dimensional products from foodstuffs, in particular from meat.
The underlying object of the invention is to develop a machine of the initially described type in such a way that formed bodies of a mouldable, in particular glutinous substance may be moulded into shape and packaged by said machine in an even shorter time than with the described known machine.
Proceeding from a machine of the described type the object is achieved according to the invention in that
said central axis is disposed transversely at a distance above the loading section,
the shaping wheel is drivable at a peripheral speed, which approximately corresponds to that of a slip-free rolling on the longitudinally moving strip-shaped packaging material,
the moulds are disposed, starting from the cylindrical peripheral surface of the shaping wheel, radially in relation to the central axis, thereof,
each mould contains a separate piston which is movable back and forth between a retracted position for filling the mould with substance and an advanced position for ejecting the consolidated formed body in a radially outward direction onto the packaging material,
the device for wrapping the formed bodies lying on the strip-shaped packaging material is formed substantially comprised of:
a bending section for upward bending of the mutually opposite side edges of the strip-shaped packaging material,
a longitudinal sealing unit for joining together the two edges of the strip-shaped packaging material, which therefore assumes a tubular shape, and
a transverse sealing unit for forming transverse seams in the strip-shaped packaging material between successive formed bodies, and in that
associated with the shaping wheel, the longitudinal sealing unit and the transverse sealing unit are drives which may be synchronized with one another for manufacturing and depositing the formed bodies and for moving and sealing the packaging material.
The peripheral speed of the shaping wheel and the linear speed of motion of the strip-shaped packaging material are vectors which, in a relatively large deposit area, are substantially identical to one another not only in their value but also in their direction. It is therefore not necessary for each formed body to be separated from the shaping wheel and taken over by the strip-shaped packaging material exactly at a specific point within the deposit area. The depositing of the formed body may accordingly occur with continuous rotation of the shaping wheel and continuous linear motion of the strip-shaped packaging material. The centrifugal force which acts upon the formed body so long as the latter is participating in the rotation of the shaping wheel, facilitates the separation of the formed body from the piston which has accompanied the formed body en route from the filling area via the consolidation area to the deposit area. After the formed body has been deposited on the packaging material, the latter is gradually deformed in that, first, its lateral edges are bent up on both sides of the formed body and then joined to one another above the formed body. Then, in the hitherto still strip-shaped, i.e. continuous packaging material transverse seams are formed between successive formed bodies and, finally, the packaging material is cut between the formed bodies. All of this helps to enable a high operating speed of the machine according to the invention.
In a preferred embodiment of the machine according to the invention the distance between the central axis of the shaping wheel and the loading section is adjustable for adaptation to formed bodies of differing height. This creates the possibility of adjusting a gap, the height of which is only slightly greater than that of the formed bodies, between the loading section and the region of the peripheral surface of the shaping wheel which is, in each case, closest to the loading section. This helps to guarantee, even at high operating speeds, a precise depositing of the formed bodies on the strip-shaped packaging material.
The pistons are preferably controlled, via a cam follower each connected thereto, by a central control cam in a manner known as such from the cited U.S. Pat. No. 1,524,915. Said control cam does not participate in the rotation of the shaping wheel and may, in the machine according to the invention, be fashioned in such a way that it is directly responsible only for a precisely defined, radially outward displacement of the pistons in the moulds en route from the filling area to the deposit area; the necessary retraction of the pistons en route from the deposit area to the filling area may be achieved by spring force. However, the central control cam may alternatively be fashioned in such a way that it likewise positively controls the radially inward retraction of the pistons, in the manner provided according to U.S. Pat. No. 1,524,915.
For processing substances requiring compression it is advantageous when the moulds along at least one part of the dwell area are sealable by means of a pressing body, which is pressable against the cylindrical lateral surface of the shaping wheel. This too is known from U.S. Pat. No. 1,524,915. In said case, the control cam in the machine according to the invention may be fashioned in such a way that it displaces the pistons in their moulds, as the latter travel from the filling area to the deposit area, in a radially outward direction until the formed bodies produced have reached a predetermined density. Independently thereof, the formed bodies produced in the machine according to the invention may be thermally treated in the dwell area by heating or cooling the moulds.
When it is a matter of manufacturing formed bodies from a glutinous substance, according to a development of the invention it is provided that disposed in the deposit area is a scraper for separating the formed bodies from the pistons. A suitable scraper is, for example, a steel wire, which extends along a surface line of the shaping wheel and is held adjacent to the latter""s cylindrical peripheral surface with sufficient force to keep said peripheral surface clean.
In said connection it is further advantageous when the pistons have an end face curved in accordance with the cylindrical peripheral surface of the shaping wheel and having a run-on bevel, which is directed forward in the direction of rotation of the shaping wheel, for the scraper.
For increasing the operating speed in the wider sense it is also advantageous when the moulds are each disposed inside a bush, which is fastened in the shaping wheel in such a way as to be exchangeable together with the associated piston. It is therefore possible to reduce resetting times when a succession of formed bodies of differing shape are to be manufactured and packaged.